The use of cobalt disilicide (CoSi.sub.2) in microelectronics applications is becoming more and more important. In CMOS technology, with the scaling down of dimensions, especially for CMOS technology manufacturing of a transistor with a gate length smaller than 0.35 .mu.m, CoSi.sub.2 has become an attractive material due to its better characteristics when compared to the more frequently used titanium disilicide (TiSi.sub.2).
The interaction of a silicide film with chemicals and reactive gasses during further processing is an important issue an maintain the integrity of the film in the fully integrated structure. TiSi.sub.2 is known to be very reactive with chemicals such as ammonium hydroxide (NH.sub.4 OH--) and hydrogen fluoride-based (HF-based) solutions. CoSi.sub.2 is much more robust in that respect. In general, wet etching of CoSi.sub.2 is considered very difficult.